Des Hasler's perfect record of preliminary final wins will be tested on Friday night when the Manly legend faces the man he turned to for advice as a rookie NRL coach.

Wayne Bennett is the most successful coach in rugby league history so it's little wonder Hasler turned to the now South Sydney man as a mentor when he first took on the Sea Eagles job in late 2003.

What eventuated was a meeting of two of the most extraordinary minds in the game, putting them on a collision course for Friday night's clash at Suncorp Stadium.

While Bennett is a veteran of 14 preliminary finals and 10 deciders as coach, Hasler holds an unblemished record in grand final qualifiers.

Eight times Hasler has won through the penultimate round of the season into a decider - three times with Manly as a player and five as a coach with the Sea Eagles and Canterbury.

He says there's no secret to success - at least not one he's willing to share.

"I don't know what the secret is, I don't think there is a secret. But that's a good fact... comforting," he said on Thursday.

"Probably being at this stage, being able to win (is the one trait a team needs).

"It's an important mentality, all players and every part of the coaching faculty knows that it's do or die and that's what makes this time or these particular games so much different to the others."

On the opposite hand, Souths are through to their fourth preliminary final in as many years and desperately need to clear the hurdle in Bennett's last season at the club.

The ex-Brisbane mentor has lost four of the past five preliminary finals he's coached in, including two with Souths and two with the Broncos - making the 2015 decider opposite eventual premiers North Queensland.

While Hasler takes comfort in his spotless preliminary final record, Bennett rubbishes it as any indicator of Friday night's outcome.

"That's a myth stat that one, what about all the prelim finals you don't make as a coach," the seven-time premiership-winner said.

"It's all about the ones he made, how many didn't he make?"

For instance, the last preliminary final Hasler didn't make was in 2019 when Bennett and the Rabbitohs knocked Manly out 34-26 in the semi-finals.

In 17 seasons Hasler has won two premierships with Manly, and in only three years did he fal to make the finals at all - in 2020 and 2004 with the Sea Eagles and in his last year with the Bulldogs in 2017.

It says something about the mentality of Hasler-coached teams and their approach to September.

"We've been good friends for a long time Des and myself, I've always admired what he's done," Bennett said.

"We used to go to Armidale camps together, he was a player and I was a coach back in the '90s and I coached against him in the 1987 grand final playing for Manly, and when he came into coaching he used to come and visit me every so often just to get a few ideas and so forth.

"We have a wonderful relationship."